The function of what are known as “transparent” satellites is essentially to amplify signals transmitted on uplinks by ground transmitting stations and then retransmit them towards ground receiving stations, via downlinks. These satellites receive sets of signals transmitted by ground transmitting stations, which are then distributed over a set of input channels and, according to a predetermined configuration, routed towards output channels to be transmitted towards the ground receiving stations. The expression used in this context is “signal routing on board a satellite”.
At the present time, the signal routing configuration in satellites is most commonly static. Thus, when a satellite telecommunications system is deployed, the power and frequency resources of the satellite are divided up by planning functions (mission planning and frequency planning) among the various satellite access networks or modem systems, acting on one transponder at a time. A certain number of channels of predetermined width is defined, and this configuration remains fixed throughout the life of the satellite. Since the life of a telecommunications satellite may be more than fifteen years, this static configuration does not allow the payload to be adapted to changes in the data traffic. Similarly, within this fixed configuration, the allocation among satellite access networks is also static. Changing this allocation requires the provision of a new plan, resulting in service interruptions.
Some satellites have flexible payloads, enabling the use of the satellite to be optimized during its life. This operation is based on “manual” replanning of the payload, and is generally carried out by engineering the established traffic or by amending the user service contracts. A drawback of this reconfiguration is that it is defined for the period of the mission, and remains fixed throughout this time.
One object of the invention is, notably, to rectify one or more of the shortcomings of the prior art by proposing a solution for automated control of the flexible equipment of a telecommunications satellite or satellites, on the basis of temporal and geographical changes in the established user flows, in compliance with the user service contracts.
To this end, the invention proposes a dynamic resource allocation method for at least one satellite access network associated with a group of at least one telecommunications satellite comprising a frequency-flexible payload, said group of at least one satellite access network comprising a plurality of resource allocation controllers, said method being executed by a dynamic resource allocation device, and comprising:
a step of acquiring a signal representing the value of bandwidth desired by each resource allocation controller of each satellite access network,
a step of reconfiguring the payload of the group of at least one telecommunications satellite, with allowance for the values of bandwidth desired by each resource allocation controller and the frequency resources available on board each satellite,
a step of frequency allocation to the various resource allocation controllers of the group of at least one satellite access network, with allowance for the values of bandwidth desired by each resource allocation controller and the frequency resources available on board each satellite.
According to one embodiment,
if the sum of the values of bandwidth desired by each resource allocation controller is less than the available frequency resources of the satellite, a dynamic frequency allocation module allocates the desired value of bandwidth to each resource allocation controller,
if the sum of the values of bandwidth desired by each resource allocation controller is greater than the available frequency resources of the satellite, a dynamic frequency allocation module allocates a predetermined value of bandwidth to each resource allocation controller.
According to one embodiment, the method further comprises, for each resource allocation controller:
a step of acquiring a signal representing the data rate of the resource allocation controller in question,
a step of calculating a rate of use of the allocated bandwidth and comparing this rate with a predetermined lower bound,
if the rate of use is less than said lower bound, a step of reducing the allocated value of bandwidth by allocating to said resource allocation controller a value of bandwidth corresponding to a rate of use substantially equal to said lower bound.
According to one embodiment, the method further comprises, for each resource allocation controller:
a step of acquiring a signal representing the data rate of the resource allocation controller in question,
if the data rate of said resource allocation controller is less than a predetermined nominal value while the value of bandwidth allocated to this controller is greater than said nominal value, a step of reducing the allocated value of bandwidth by allocating to said resource allocation controller a value of bandwidth substantially equal to said nominal value.
According to one embodiment, the method further comprises a step of acquiring a signal representing the quality of service associated with the data to be transmitted by each resource allocation controller and according to which the dynamic resource allocation device increases the priority of the value of bandwidth of the resource controllers having the highest priority, using said quality data.
According to one embodiment, at least one satellite is of the multi-channel type and according to which the method further comprises a step of modifying the gain of at least one of the channels of at least one telecommunications satellite.
The invention also proposes a dynamic resource allocation system for executing the method described above, comprising a dynamic resource allocation device, at least one satellite access network, and at least one communications satellite comprising a frequency-flexible payload,
said group of at least one satellite access network comprising a plurality of resource allocation controllers, each resource allocation controller being configured to transmit data to at least one modem, each resource allocation controller being connected to the dynamic resource allocation device, and each resource allocation controller being configured to deliver a signal representing the desired value of bandwidth and to transmit this signal to the dynamic resource allocation device,
said dynamic resource allocation device comprising at least one calculation module configured to execute the method previously described, and at least one module configured to allocate a value of bandwidth to the various resource allocation controllers of the group of at least one satellite access network and to reconfigure the payload of each satellite of the group of at least one telecommunications satellite.